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Objective: To establish a convenient non-invasive tracheal perfusion method for constructing a mouse model of silicosis-induced pulmonary fibrosis. Methods: The specific pathogen-free C57BL/6 mice were randomly divided into control group and model group, with 15 mice in each group. After anesthesia, a 22G arteriovenous indwelling needle was used to inset into the trachea through the mice's mouth. The model group mice were perfused with 0.1 mL of silica suspension with a mass concentration of 25 g/L, and the mice in the control group were perfused with an equal volume of 0.9% sodium chloride solution. On the 7th, 14th, and 30th day after modeling, the body weight of the mice was measured, and the lung tissue morphology and pathological changes were observed. The expression of α-smooth muscle actin (α-SMA) and collagen type 1 alpha 1 (COL1A1) protein in lung tissue of mice was detected by immunofluorescence on the 30th day after modeling. Results: There was no death of mice in the two groups during the experiment. There was no significant difference in body weight between the two groups (P>0.05). The lung tissues of the mice in the model group were pinkish-gray and uneven in color on the 7th and 14th days after dust exposure. On the 30th day after dust exposure, the lung tissue of the mice in the model group was gray and hard, and unevenly distributed silicon nodules were visible by the naked eyes. The histopathology results of lung tissue showed that compared with the mice in control group, the model group mice exhibited persistent aggravation of pulmonary inflammation, thickening of alveolar septum, infiltration of inflammatory cells gradually clustering into clumps, and an increasing number of fibrous foci.On the 30th day after dust exposure, the relative expression of α-SMA and COL1A1 proteins in the lung of the model group was higher than those in the control group (median： 72.59 vs 5.91, 35.62 vs 10.07, both P<0.05). Conclusion: The method of tracheal perfusion silica suspension of mice using 22G arteriovenous indwelling needle can successfully construct an animal model of silicosis fibrosis. This method is convenient, safe and effective, and is worth promoting.
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Objective@#To investigate the effect of chrysotile exposure on ribosomal DNA (rDNA) copy number and DNA damage response, so as to provide insights into the mechanism of asbestos-induced carcinogenesis. @*Methods@#Human pleural mesothelial MeT-5A cells were treated with chrysotile suspensions at doses of 1.25, 2.5 and 5 μg/cm2 (low-, medium-, high-dose group), while PBS served as controls. MeT-5A cells were harvested 6, 24, 48 and 72 h post-treatment, and the rDNA copy numbers and the BIRC5, HRAS, GINS4 and RRM2 mRNA expression were determined using a quantitative real-time PCR (qPCR) assay. The apoptosis of MeT-5A cells and DNA damage were detected using Muse cell analyzer. The rDNA copy numbers, DNA damage responses and BIRC5, HRAS, GINS4 and RRM2 mRNA expression were compared in MeT-5A cells treated with different doses of chrysotile suspensions.@*Results@#There were significant differences in 45S rDNA copy numbers among low-, medium-, high-dose groups and the control groups 6, 48 and 72 h post-treatment with chrysotile suspensions, and significantly lower 45S rDNA copy numbers were measured in low-, medium- and high-dose groups than in the control group 6 h post-treatment, while significantly higher 45S rDNA copy numbers were found in the high-dose group than in low- and medium-dose groups 48 and 72 h post-treatment (all P<0.05). There were significant differences in 5S rDNA copy numbers among low-, medium-, high-dose groups and the control groups 24, 48 and 72 h post-treatment with chrysotile suspensions, and significantly lower 5S rDNA copy numbers were measured in medium- and high-dose groups than in the control group 24 and 48 h post-treatment, while significantly lower 5S rDNA copy numbers were found in medium- and high-dose groups than in the low-dose group 24, 72 h post-treatment (all P<0.05). There were significant differences in the overall apoptotic rate of MeT-5A cells among groups at different time points, and the overall apoptotic rate of MeT-5A cells were significantly higher in medium- and high-dose groups than in the control group (all P<0.05), with late-stage apoptosis predominantly detected. There were significant differences in the rates of ATM activation and DNA double-strand break in MeT-5A cells among groups 72 h post-treatment, and higher rates of ATM activation and DNA double-strand break were measured in medium- and high-dose groups than in the control group (all P<0.05). In addition, there were significant differences in the relative mRNA expression of BIRC5, HRAS, GINS4 and RRM2 genes among groups 24 and 48 h post-treatment, and significantly lower BIRC5, HRAS, GINS4 and RRM2 mRNA expression was quantified in medium- and high-dose groups than in the control group (all P<0.05).@*Conclusion@#Exposure to chrysotile may induce rDNA copy number variations and altered expression of nucleolar proteins in human pleural mesothelial cells, which may be involved in the regulation of DNA damage responses.
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Objective To explore the relationship between vitamin D and depression and the effects of chronic unpredictable mild stress (CUMS) plus sertraline on vitamin D metabolism in rat brain.Methods Male SD rats were randomly divided into normal control group,normal control + sertraline group,CUMS group and CUMS+sertraline group.CUMS was used to build the animal model of depression.After chronic exposure to CUMS or sertraline (8 mg·kg-1·d-1) for 6 weeks,behavioral response (sucrose preference test) and vitamin D metabolism in the prefrontal cortex were analyzed.Results Compared with normal control group,6 weeks of CUMS procedure induced the rats to a depression-like state,decreased weight and sucrose preference,and increased the expression of enzymes involved in vitamin D activation and catabolism (CYP27B1 and CYP24A1,respectively) and vitamin D receptor (VDR) in rat prefrontal cortex.As compared with CUMS group,CYP27B1,CYP24A1 and VDR were significantly decreased in CUMS+sertraline group (P<0.01 or P<0.05).Conclusion CUMS activates vitamin D signaling in the brain of the animal models of depression,while sertraline alleviates depressive behavior and relieves stress-induced activation of vitamin D signaling,indicating that vitamin D signaling may be involved in the stress-induced depression.
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Objective To evaluate the efficacy and safety of recombinant human endostatin (rh-endostatin) combined with cis-platinum for patients with malignant pleural effusions.Methods A computer-based online search was performed through Elsevier, PubMed, Medline, Cochrane Library, China National Knowledge Infrastructure (CNKI), Chinese BioMedical Literature Database and Wanfang Database.According to the inclusion and exclusion criteria, the randomized controlled trials about short-term therapeutic effect of rh-endostatin combined with cis-platinum on malignant pleural effusions published until December 2015 were selected.Quality of the studies was assessed using modified Jadad scale.After data extraction, a Meta-analysis was performed by RevMan 5.3 software.Relative risk (RR) and its 95% confidence interval (CI) were calculated.The Egger test was performed by Stata 12.0 software.Results Fourteen eligible randomized controlled trials were included in this Meta-analysis involving 1 330 patients,665 in cis-platinum alone group(control group), and 665 in rh-endostatin combined with cis-platinum group(treatment group).The results showed that there were significant improvements in overall response rate (ORR) [73.53% vs 45.41%,RR=1.62,95%CI(1.47,1.78),P<0.000 01] and the rate of quality of life improvement [71.65% vs 46.94%,RR=1.52,95%CI(1.38,1.68),P<0.000 01] in the treatment group, as compared with those of the control group.Meanwhile, there were no statistically significant differences in the rate of cardio toxicity [10.38% vs 5.77%,RR=1.73,95%CI(0.99,3.03),P=0.06].Conclusion This Meta-analysis indicated that in comparison with cis-platinum alone, rh-endostatin combined with cis-platinum has a better therapeutic effect on malignant pleural effusions.